Conventional cable tv systems deliver video data from a distribution company through a cable to monitors of a number of viewers. Although nowadays many programs are distributed through many channels by each cable tv company, the user or viewer has to wait until the desired program is started and transmitted through a selected channel.
Recently, also interactive video systems have been proposed. In such interactive video system a viewer can chose a desired movie to be displayed on the monitor of said viewer. In such video-on-demand system a direct connection to the monitor or end device of a user is established, whereafter a demanded movie can be viewed by the end user.
In this known system it is however virtually impossible to upscale the system after it has been established e.g. by a distribution company. When the number of members for such a system increases and the number of demanded videos is increased, a new interactive video system has to be built.
The present invention provides a system for serving information data to one or more end devices of one or more users, comprising:
one or more storage medium units for storing information data;
managing means for managing distribution of the information data to any one of the end devices, wherein the managing means receive demand data relating to information data selected by the user through his device, and wherein the managing means output distribution control data including channel information of the selected information data and routing information for said end device; and
routing means for connecting the storage medium unit to the end device, and for routing the information data from the storage medium unit and the distribution control data from the managing means.
This system according to the present invention provides a sort of platform and can operatively be connected to an end user through a public network, can operate as a stand alone system operatively connected to end devices, in which latter case the system according to the present invention is also provided with navigation devices for presenting possible choices for an end user entering the system.
Preferably the routing means comprise at least one ATM switch. The basics and standards of ATM (Asynchronous Transfer Mode) are laid down in recommendations I.150 and I.327 as published in March 1993 by the International Telecommunication Union. ATM is generally used for addressing a specific packet-oriented transfer mode which uses asynchronous time division multiplexing techniques. The multiplexed information flow is organized into blocks of fixed size, where said blocks are referred to as cells. A cell consists of an information field and a header. The primary role of the header is to identify cells belonging to the same virtual channel within the asynchronous time division multiplex.
Preferably said information data is video and/or audio data although the present invention is not limited to this application. A system according to the present invention may also comprise applications for video-games, library functions, databanks etc., although a first promising application field relates to video on demand services.
In case the information server system according to the present invention is connected to a public network, the demand data preferably includes a public address to be assigned to the selected information data.
Preferably the managing means provide program data for information retrieval to the end device, so that an end device will be downloaded with such program data from the system. This feature provides the additional advantage that the end device only needs to include very little software for starting up purposes etc.
Although in a small scale configuration, such as in an hotel accommodation or to like, the information services system according to the present invention may comprise only one storage medium unit (and even one end device), the system according to the present invention preferably comprises at least one second storage medium unit. In such a case the managing means comprise a table for storing data representing information data allocation to the first and second storage medium unit on basis of demand data from an end device. In this way the managing means manage the switching of the ATM switch for establishing virtual channels between the end device and the storage medium unit.
Preferably the storage medium unit according to the present invention comprises;
memory means for storing video and/or audio data;
table means for memorizing data representing a relationship between the routing information and the video and/or audio data stored in the storage means;
program memory means for storing program data for control of the operation of the storage medium unit;
control means for controlling the memory means, the table means and the program memory means according to program data and for outputting one or more control signals to the end device; and
at least one interface for transmitting the video and/or audio data with the routing information and a control signal in the form of one or more packets to the routing means and for receiving program data for operation of the storage medium unit in the form of one or more packets from the routing means. The memory means can comprise a magneto-optical (MO) disc or hard disc which is more agile than a MO disk. Also, preferably the routing information is supplied to the ATM interface of the storage medium unit.
Preferably the information server system in a video and/or audio data application is capable of providing still mode, fast forwards mode, reverse mode, fast reverse mode as in VCR (video cassette recorder) and a mosaic mode operation.
To prevent time delay even in less agile memory means of the storage medium unit, preferably video and/or audio data is divided in a predetermined number of data groups arranged in a sequence different from the original sequence.